Exhaust recycle on deceleration with purging system for filter



' B. WALKER 3,491,736

EXHAUST RECYCLE 0N DECELERATION WITH PURGING SYSTEM FOR FILTER Jan. 27, 1970 v Filed July 26, 1967 //V V5 11/ 7'01? BROOKS WALKER mix. SQQWM Emma United States Patent 3,491,736 EXHAUST RECYCLE ON DECELERATION WITH PURGING SYSTEM FOR FILTER Brooks Walker, 1280 Columbus Ave., San Francisco, Calif. 94133 Filed July 26, 1967, Ser. No. 660,861 Int. Cl. F02m 7/00 [1.8. Cl. 123-119 9 Claims ABSTRACT OF THE DISCLOSURE This invention pertains to a system of automatically shutting 01f the exhaust and fuel on deceleration and recycling the exhaust through the engine through a cannister filter using an absorbent such as activated carbon. Also, it relates to a system of cannister purge control that operates when the engine is developing power to purge the cannister filter by drawing clean air through the cannister and into the engine in limited quantities on selected engine operating conditions.

An object of this invention is the improvement of the recycle controls for shutting off the exhaust and opening the path from the exhaust to a cannister with the same valve, shutting off the fuel supply simultaneously on deceleration and opening a valve to circulate the gases entering the exhaust through the intake manifold and through a cannister filter. A recycle on deceleration is shown in my pending U.S. patent application Ser. No. 441,710, entitled Engine for Reduced Exhaust Smog Emissions, dated Mar. 22, 1965, now Patent Number 3,368,345, issued Feb. 13, 1968, but no means of filtering the circulating gases from the exhaust on deceleration.

Another object is the method of purging a cannister that absorbs gases developed in this system or any other by a suction sensitive valve that closes olf the purging on idle and opens it to varying degrees as the suction drops below idle suction, such as starting to open at about 1213 Hg intake suction or by an engine speed sensing valve to be open above 1000 r.p.m. but also with a suction operated valve so that the recycle opening is less at 13" Hg suction than at 8" suction.

Another object is a check valve in the clean air to the cannister purge circuit as when recycling the exhaust on deceleration there will probably be a positive pressure in the exhaust and a negative pressure in the intake so the check will prevent exhaust in going out through the clean air passage to the cannister,

The control of the exhaust recycle on decelerations by two valves in series-one a valve or port that is open when the throttle is closed, as shown in my US. Patent No. 3,162,184, Spark Timing Control, Dec. 22, 1964, in series with a speed sensing valve open above a predetermined engine speed by mechanism, such as is shown in my US. Patent No. 3,204,620, Speed Sensing Valve, Sept. 7, 1965.

Another object is to have the valve that closes the exhaust on decelerations also close on a second seat to close off communicatin of exhaust to the line going t the cannister of absorbent when not in deceleration operation.

Other objects will be more particularly pointed out in the accompanying specifications and claims.

I have shown my invention in the accompanying drawing wherein FIG. 1 is a side view, partly in section and partly diagrammatic, of an engine embodying one form of the invention, and FIG. 2 is a section showing an alternative form of the invention.

In the drawing I have shown an engine with a carburetor 11 with a throttle valve 12. A throttle valve control arm 13 and a link 14 actuated by the control arm 13 to actuate a valve E when the throttle is closed or after closing, as shown in my said US. Patent No. 3,162,184. A high port 23 may be connected to line 22 in place of valve E which is open when throttle 12 is closed or in engine idle position.

When deceleration above a selected engine speed as sensed by motor M from a pitot pickup in the waterpump as described in my said US. Patent No. 3,204,620, suction from the intake manifold 25 will flow through line 16, valve E (or port 23 and line 22 as chosen by design) through line 17, valve F (open above a selected engine speed), line 18, line 19 to motor MM which lowers valve 30 from seating on seat 31, as shown, to seating on seat 32 to close off the flow of exhaust to pipe 55. Suction also flows through line 20 to valve B which then opens to allow the gases from the exhaust manifold 35 to flow through exhaust pipe 36 past valve 30 on seat 32 up through conduit 37 to cannister 38 with absorbent 39 (such as activated carbon) line 40 through valve B opened by suction from line 20 and 20a and conduit 41 to the engine side of butterfly 12. Suction from line 20 can also flow through line 21 to motor 45 which shuts off the fuel to idle from line 64 on such closed throttle decelerations by means as shown in said Ser. No. 441,710. The recycled exhaust gases will be cleaned by activated carbon 39 in cannister 38 during such deceleration.

As power is resumed, suction in control line 17 will be shut off by valve E or port 23, depending on which is used so the fuel to idle is on by motor 45 and the exhaust recycle is closed oil? by valve 30 being in the position shown and valve B being closed when no suction is available in lines 20 and 20a to actuate them to the recycle position. As power is developed over a predetermined engine speed, valve A opens to allow fresh air from air cleaner 50 to flow through line 51, check valve D, line 52 through filter material 39 through line 40, line 42, valve A, line 43 to the engine side of butterfiy 12 in carburetor 11. Valve A is open above a selected engine speed as by a motor such as M and a suction o erated valve C in series that leaves the valve closed at idle but open a little at suctions less than idle, such as cruise suction and open more at suction such as 8" Hg to purge the contents 39 of cannister 38 and get ready for another deceleration. In this way, when valve 30 goes from the lower exhaust closed position when seated on seat 32 to the position shown the contents of the recycled exhaust gases will be much purer when released into the exhaust pipe 55 and mufller 56 than if an absorbing cannister were not used. This system could be used with a fuel injection system by shutting off the fuel to idle and using the same valves to control the recycling cannister and cannister purge.

I have illustrated my inventions in these various forms; however, many other variations may be possible within the scope of this invention.

To those skilled in the art to which this invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and description herein are purely illustrative and not intended to be in any sense limiting.

I claim:

1. An internal combustion engine having a fuel feeding system, an engine speed sensor, an intake manifold and an exhaust manifold, an exhaust outlet pipe, a re cycle path from the exhaust to the intake manifold, a first valve system for closing off the exhaust from reaching said exhaust outlet pipe and opening a path for all of said exhaust to said intake manifold, a cannister in said "ice recycle path with absorbent material for absorbing unburned hydrocarbons and some other components of the exhaust when conducted through said cannister and absorbent, a second valve system for admitting clean air to said cannister and absorbent and conducting said clean air through said absorbent and to said :engine in'limited quantities during certain cycles of operation of said engine when under power greater than idle power, said first valve system being associated with said fuehfeeding on closed throttle deceleration above a predetermined engine speed, said fuel Will be closed off and said exhaust conducted to said intake manifold by 'said first valve system and when power above idle is resumed air will, be drawn through said cannister and absorbent to said intake manifold by said second valve system.

2. An internal combination engine having an air intake system, a fuel feeding system, an exhaust system, a throttle control of the fuel to said engine for power control, a capnister with absorbent, a first valve system for conducting all the gases from said exhaust system to said intake system through said cannister and simultaneously shutting off said fuel supply to said system during closed throttle decelerations above a selected engine speed, a second valve system for conducting air through said cannister to said intake system in limited quantities during selected power operations of said engine when said fuel supply system is supplying fuel to said engine to conduct the air with fuel from said absorbent in said cannister to said intake manifold.

3. An internal combustion engine having an exhaust system, an intake system, a system for recycling exhaust to the intake of said engine, a cannister with absorbent material in said recycling system, said exhaust recycle system having valve means responsive to engine operating condition to permit an exhaust volume going through said cannister on a selected engine operating condition, and means for drawing fresh air through said cannister and to said intake system to said engine during some engine power operating conditions when power is being developed and no recycle from said exhaust system to said intake system is taking place.

4. An internal combustion engine having an intake manifold, an exhaust manifold, conduit means for circulating exhaust gas through said manifolds, a filter in said conduit means for absorbing selected elements from circulated exhaust gas, and a valve in said conduit means moveable between one position for connecting all exhaust gas generated by the engine to discharge and a second position for circulating all the said generated gas through the filter on closed throttle deceleration of engine speed.

5. A device as defined in claim 4 further including a motor connected to the valve for shifting and holding the valve at said positions. 5

6. A device as defined in claim 5 wherein said motor is fluid operated, a supply conduit connected to said motor and intake manifold to supply intake manifold pressure toihe motor, a first valve in said supply conduit responsive to the speed of the engine for controlling the flow of fluid therethrough, and a second valve in said conduit for controlling the flow of fluid therethrough in response to the position of the throttle.

7. An internal combustion engine having an intake manifold, an exhaust manifold, conduit means for circulating exhaust gas through said manifolds, a filter in said conduit means for absorbing selected elements from circulated gas, and means for closing said conduit means to prevent circulation of gas through said manifolds and filter, and duct means for conducting air through the filter to the intake manifold when the conduit means is closed between idle and on deceleration below a predetermined engine speed.

8. A device as defined in claim 7, a throttle valve for controlling the flow of fuel said intake manifold wherein the means for closing said conduit comprises a valve therein responsive to a preselected engine speed and position of said throttle.

9. A device as defined in claim 8 further including a valve in said duct means operated to open above said preselected engine speed.

References Cited UNITED STATES PATENTS 2,147,670 2/ 1939 Pratt. 2,696,202 12/ 1954 MacDonald. 2,700,967 2/1955 Maker. 2,722,927 11/ 1955 Cornelius. 2,741,233 4/1956 McKinley. 2,889,904 6/1959 Martinoli. 3,035,561 5/1962 Siegler. 3,093,124 6/1963 Wentworth l23l36 3,368,345 2/1968 Walker.

AL LAWRENQE SMITH, Primary Examiner 

